GRAAD 12 NATIONAL SENIOR CERTIFICATE GRAD E 12 · Various options are provided as possible answ ers to the following questions. Choose the answer and make a cross (X) in the block

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This question paper consists of 12 pages and 1 answer sheet.

GRAAD 12

AGRICULTURAL TECHNOLOGY

NOVEMBER 2012

NATIONAL SENIOR CERTIFICATE

GRADE 12

Agricultural Technology 2 DBE/November 2012 NSC


INSTRUCTIONS AND INFORMATION 1. GENERAL INSTRUCTIONS AND INFORMATION 1.1

1.2

This question paper consists of TWO sections, namely SECTION A and SECTION B. BOTH sections are COMPULSORY.

2. SECTION A: MULTIPLE-CHOICE QUESTIONS 2.1

2.2 2.3

Answer the questions in this section on the attached ANSWER SHEET. Follow the instructions when answering the multiple-choice questions. Place the COMPLETED ANSWER SHEET in the ANSWER BOOK.

3. SECTION B: STRUCTURED QUESTIONS 3.1

3.2 3.3 3.4 3.5

This section consists of FIVE questions. Answer the questions in this section in the ANSWER BOOK. Number the answers correctly according to the numbering system used in this question paper. Start EACH question on a NEW page. Non-programmable calculators may be used.



SECTION A QUESTION 1

Various options are provided as possible answers to the following questions. Choose the answer and make a cross (X) in the block (A–C) next to the question number (1.1–1.20) on the attached ANSWER SHEET.

EXAMPLE: 1.0 A B C 1.1 Pesticide spraying equipment uses … substances and must be used with

extreme care and under supervision.

A

B C

sticky hazardous slippery

(2) 1.2 …, as a result of exposure to the noise of equipment, is a state of health that

can be permanent.

A

B C

A lung disease A back problem Hearing loss

(2)

1.3 Minor cuts and scrapes suffered in the workshop must be … by the teacher. A

B C

disinfected and left alone disinfected left alone

(2)

1.4 This type of fire should be tackled with dry powder or CO2 extinguishers after

disconnecting the …

A

B C

electricity supply. water supply. foam supply.

(2) 1.5 The incorrect use and disposal of agricultural chemicals … A

B C

can cause respiratory diseases and injuries. can cause cancer in humans and animals. Both A and B

(2) 1.6 Stainless steel can be produced by melting chrome, manganese and ...

together.

A B C

mild steel nickel copper

(2)



1.7 The function of the … in a vehicle is to ensure that the gears can be changed

while the vehicle is moving.

A B C

differential clutch gearbox

(2)

1.8 Mild-steel sheets are often galvanised to prevent them from …

A B C

getting too hot. rusting. getting too cold.

(2)

1.9 … is a plastic that is extremely heat resistant. A

B C

Bakelite Perspex Teflon

(2) 1.10 The catalyst and … can have an influence on the speed of the hardening

process of adhesives.

A

B C

cohesion force accelerator adhesion force

(2) 1.11 To improve the cohesion properties of an adhesive one can … A

B C

apply water to the surface before the adhesive is applied. apply adhesive to both surfaces. warm up the surface before applying the adhesive.

(2) 1.12 Resin is a fluid with low viscosity that can be transformed into a tough, flexible

solid by adding a … agent.

A

B C

glue hardening silicon

(2) 1.13 The size of a normal foundation, as stipulated in the code for building, is … A

B C

600 mm × 230 mm. 800 mm × 600 mm. 400 mm × 200 mm.

(2) 1.14 Press wood is not a suitable material for the manufacturing of roof trusses

because it …

A

B C

is too brittle. deteriorates in moist conditions. Both A and B

(2)



1.15 Triangular constructions are used in the design of roofs because they

strengthen the construction so that the … can carry the weight of the roof.

A

B C

trusses beams purlins

(2) 1.16 The warning signs on all electric fences should be at least … in size. A

B C

100 mm × 200 mm 900 mm × 800 mm 100 mm × 100 mm

(2)

1.17 To prevent the driver of a tractor from inhaling exhaust gases the …. A

B C

manifold of the tractor may be enlarged. exhaust of the tractor may be lengthened. exhaust of the tractor may be shortened.

(2)

1.18 To prevent loose soil and stones from falling into a borehole, the borehole

should be …

A

B C

drilled. lined. plastered.

(2)

1.19 The gas that provides the flame when using the oxy-acetylene welding

process is …

A

B C

argon gas. oxygen. acetylene gas.

(2) 1.20 Which ONE of the following is NOT an advantage of a combine harvesting

machine?

A

B C

It is a time- and labour-saving machine. It requires a large financial input. Accurate record-keeping is possible.

(2)

TOTAL SECTION A: 40



SECTION B QUESTION 2: MATERIALS AND STRUCTURES

2.1 Name THREE methods, besides tinning, that can be used to protect metals

against the elements of nature.

(3)

2.2 Discuss any FIVE characteristics of adhesives.

(10)

2.3 Explain the functions of brandering in the roof construction of a building on the farm.

(3)

2.4 Name any type of insulation material that can be used between the roof and the ceiling to keep a shed cool in summer and warm in winter.

(1)

2.5 Large structures place extreme stress on their foundations with the result that some foundations tend to crack because of the weight.

2.5.1 Describe any TWO methods of strengthening these foundations.

(4)

2.5.2 Name THREE basic requirements of the foundation if the structure is built on sandy soil.

(3)

2.6 Give a valid reason for each of the following statements:

2.6.1 Clear fibre-glass roof plates are used on the roof of a greenhouse.

(1)

2.6.2 An effective game farm fence must be 2,4 metres high.

(1)

2.6.3 The wires in a fence must not be tensioned too much on a hot day.

(1)

2.6.4 The best shape that can be used for the construction of tunnels is a half-round shape.

(1)

2.6.5 Exposed water pipes tend to freeze during winter and are therefore insulated.

(1)

2.7 State FOUR uses of galvanised steel sheets.

(4)

2.8 Name TWO methods to cure concrete.

(2) [35]



QUESTION 3: ENERGY 3.1 Choose a word from COLUMN B that matches the description in COLUMN A.

Write only the word next to the question number (3.1.1–3.1.5), for example 3.1.6 Petroleum.

COLUMN A COLUMN B

3.1.1 3.1.2 3.1.3 3.1.4 3.1.5

An alcohol biofuel used in racing cars Gas from earth gas or landfills Fermenting and then distilling starch and sugar crops Made from crude oil Transesterification of fatty acids

biodiesel petroleum methane ethanol methanol

(5 x 1) (5) 3.2 Electricity in any form is very dangerous. To reduce the risk of a fatal

electrical shock one has to be very careful and must adhere to all safety regulations that are applicable to electrical equipment. Name FOUR dangerous situations leading to workers being shocked by electricity.

(4)

3.3 Explain the process of effectively transforming wind energy into a form of electrical power.

(6)

3.4 Briefly describe the concept biofuel. (2)

3.5 State THREE advantages of biofuel. (3) [20]



QUESTION 4: SKILLS AND CONSTRUCTION PROCESSES 4.1 The sketch below shows a MIG welding process. Study it and answer the

questions that follow.

4.1.1 Identify parts A to E.

(5)

4.1.2 What does the abbreviation MIG stand for?

(3)

4.1.3 State FIVE advantages of MIG welding. (5) 4.2 The picture below shows an inverter welder that is used on a farm for general

welding purposes.

4.2.1 Name the type of current produced by the welding machine above.

(1)

4.2.2 Give FIVE reasons why a farmer should consider buying an inverter welder.

(5)

4.2.3 Is it possible to weld aluminium with the inverter welder? Motivate your answer.

(2)

B

A

C D

E



4.3 Make a neat, labelled sketch of the forehand welding technique when welding

with an oxy-acetylene welding apparatus. Marks will be awarded for: Labels 5 Sketch 2 Neatness 1

(8)

4.4 Describe the term shrinking of welding joints.

(4)

4.5 Explain the process of hard facing of worn metal parts. (2) [35]



QUESTION 5: TOOLS, IMPLEMENTS AND EQUIPMENT 5.1 The picture below shows a power take-off (PTO) shaft that is used as a drive

link between the tractor and the implement.

5.1.1 Name the device that enables the power take-off shaft to operate at an

angle.

(1)

5.1.2 State the function of the grease nipple installed on this device.

(1)

5.1.3 The power take-off shaft must always be screened off to prevent it from injuring people. Name TWO requirements of these screens.

(2)

5.2 When a baler is stored in the off season there are important procedures that

must be followed. Name any FIVE procedures.

(5)

5.3 Gearboxes are used in vehicles to make it possible to select the correct gear ratio for the job that must be done.

5.3.1 Name THREE different types of gearboxes that can be used in a vehicle.

(3)

5.3.2 What is the disadvantage of straight-cut gears? (1)



5.4 A farmer wants to pump water from a river with an electrical motor and a

centrifugal pump. The diameter of the pulley on the motor is 200 mm and the r/min is 1 500. The speed of the centrifugal pump, as indicated on the manufacturer's label, is 3 000 r/min.

5.4.1 Calculate the diameter of the pulley on the pump for optimal efficiency.

Use the following formula: Na x Da = Ng x Dg Show ALL calculations.

(3)

5.4.2 The drive between the motor and the pump in the sketch above is brought about by V-belts. Describe TWO advantages of V-belts.

(2)

5.4.3 Give a reason for crossing the belt as indicated in the above sketch. (1) 5.5 Buying a new tractor is a very costly undertaking for a farmer.

5.5.1 Name FIVE factors that need to be considered before buying a new tractor.

(5)

5.5.2 Name FOUR factors that need to be considered in terms of drive/torque when tractors are purchased.

(4)

5.6 The picture below shows a baler that is used to make round bales on a farm.

5.6.1 Name the TWO different baling systems found in round balers.

(2)

5.6.2 Tabulate FIVE advantages of the ram/rectangular baler and the round

baler.

(10) [40]

Driving pulley Driven pulley


Copyright reserved

QUESTION 6: WATER MANAGEMENT

6.1 Drainage of soil with a low infiltration tempo is of the utmost importance to a crop farmer.

A flooded/waterlogged field

6.1.1 Name THREE disadvantages of closed drains.

(3)

6.1.2 Briefly discuss the construction of a closed drain.

(5)

6.2 Irrigation pipes are sometimes buried beneath the soil. Describe THREE precautionary measures that should be taken when these pipes are laid.

(3)

6.3 A septic tank serves as a reservoir where solids accumulate and are gradually broken down by bacterial action.

6.3.1 Briefly explain how a septic tank functions.

(3)

6.3.2 Identify the places where a septic tank should NOT be built.

(4)

6.3.3 Maintenance of a septic tank is very important. Give reasons for this statement.

(3)

6.3.4 Name FIVE important measures which users of septic tank systems must keep in mind if they want the system to function properly.

(5)

6.4 Water scheduling is the process used by irrigation system managers to determine the correct frequency and duration of watering, and the quantity of water applied to crops. Give TWO reasons why irrigation scheduling is necessary.

(2)

6.5 What is the maximum depth of a well? Motivate your answer. (2) [30]

TOTAL SECTION B:

GRAND TOTAL: 160

200

Agricultural Technology DBE/November 2012 NSC

Copyright reserved

ANSWER SHEET CENTRE NUMBER: EXAMINATION NUMBER: SECTION A QUESTION 1

TOTAL SECTION A (20 x 2): 40

TOTAL:

1.1 A B C

1.2 A B C

1.3 A B C

1.4 A B C

1.5 A B C

1.6 A B C

1.7 A B C

1.8 A B C

1.9 A B C

1.10 A B C

1.11 A B C

1.12 A B C

1.13 A B C

1.14 A B C

1.15 A B C

1.16 A B C

1.17 A B C

1.18 A B C

1.19 A B C

1.20 A B C


MARKS: 200

This memorandum consists of 11 pages.

AGRICULTURAL TECHNOLOGY

NOVEMBER 2012

MEMORANDUM

NATIONAL SENIOR CERTIFICATE

GRADE 12

GRADE 12

Agricultural Technology 2 DBE/November 2012 NSC – Memorandum


SECTION A QUESTION 1

TOTAL SECTION A (20 x 2): 40

1.1 A X C

1.2 A B X

1.3 X X C

1.4 X B C

1.5 A B X

1.6 X X C

1.7 A X X

1.8 A X C

1.9 X B C

1.10 A X C

1.11 A X C

1.12 A X C

1.13 X B X

1.14 A B X

1.15 X B C

1.16 X B C

1.17 A X C

1.18 A X C

1.19 A B X

1.20 A X C



SECTION B QUESTION 2: MATERIALS AND STRUCTURES 2.1 • Electroplating.

• Painting Powder coating/Rubberizing. • Galvanising.

(3)

2.2 • Heat resistance. (Temperature) The adhesive itself should not distort, melt or burn when heated. • Water-resistance.

When placed in humid conditions, a water resistant adhesive should not dissolve/weaken in the water.

• Elasticity. If we want to join elastic materials, we would use an adhesive, which would still be elastic after it has become dry, e.g. Bostik and Prestik. • Load capacity. The adhesive should be able to withstand tension. • Inflammability.

The adhesive itself must comply with the same properties where it is subjected to open flames or heat.

• Duration of cohesion/adhesion. The period of time that an adhesive will stick, after been applied to join materials.

• Duration of usability. The catalyst and the accelerator can have an influence on the speed and usability of the adhesive after being mixed. (Any 5)

(10)

2.3 • It connects the different roof trusses together and keeps the spaces correct/strengthening.

• Hold trusses upright. • Roof and ceiling is fastened to it. (Nails or screws)

(3)

2.4 Pink aerolite. (Any acceptable answer)

(1)

2.5 2.5.1 Strengthening with reinforcement. Reinforcement beams must be placed in a crisscross pattern in the cement foundation to prevent the shifting and cracking of the foundation. Thickness of the foundation. The thickness of the foundation must correlate with the weight of the structure. (Any 2)

(4)

2.5.2 • Make sure the size/measurements of the foundation are correct.

• The mixture of the cement in the foundation. • Drainage of exess water away from the foundation.

(3)



2.6 2.6.1 For sun light/radiant energy penetration into room.

(1)

2.6.2 Some game species can jump over the fence.

(1)

2.6.3 The wire will shrink on a cold day and break.

(1)

2.6.4 Half round forms will give a stronger structure against strong winds.

(1)

2.6.5 Isolation keeps the water from freezing inside the pipes during winter preventing the pipes from bursting.

(1)

2.7 • Roofs • Water troughs • Water buckets • Gutters • Housing (Any 4)

(4)

2.8 • Keep concrete moist and covered for at least 7–10 days afterwards. • Paint with curing paint.

(2)

[35]



QUESTION 3: ENERGY 3.1 COLUMN A COLUMN B

3.1.1 3.1.2 3.1.3 3.1.4 3.1.5

An alcohol biofuel used in racing cars Gas from earth gas or landfills Fermenting and then distilling starch and sugar crops Made from crude oil Transesterification of fatty acids

methanol methane ethanol petroleum biodiesel

(5)

3.2 • Damaged insulation material.

• Inadequate or faulty earth leakage protection. • Open electric wires. • Overloading of electric installations. • Wrong connection of electric wires. • Lack of knowledge. (Any relevant answer)

(Any 4)

(4)

3.3 • You need to be able to capture energy

• from the force of the wind, • through the use of a wind turbine • with a propeller blade type design. • The turbines are attached to a generator • which enables the generator to produce electrical power.

(6)

3.4 Bio-fuel is any plant or animal matter (organic material/residues) that is combustible and used as a fuel.

(2)

3.5 • Cheaper solution to our energy needs/low cost.

• Biodegradable./Regenerate faster than conventional fuels • Are renewable sources of energy. • Can help prevent engine knocking. • Less pollution-environmental friendly • Engines do not require any radical changes to switch to use these fuels. (Any 3)

(3)

[20]



QUESTION 4: SKILLS AND CONSTRUCTION PROCESSES 4.1 4.1.1 A Direction of travel.

B Electrode. C Base metal/Work piece. D Weld metal/bead. E Gas shield.

(5)

4.1.2 MIG = Metal Insert/Inert Gas.

(3)

4.1.3 • High welding speed/Faster. • Important savings in materials and weight. • High mechanical properties of welding joints. • Neat and smooth seam surface. • Guaranteed welding strength for root and layer welding. • Safety against cold shuts and cracks. • Welding in all positions, vertical up, down and overhead. • Excellent fusion and penetration. • Operation requires less manual skills. • Welding area is easier to see. • No heavy slag to control or to chip away, compressed gas

seals the weld pool. • Potentially cheaper. • Welds a wider range of thickness. • Welding wire runs from a spool and need not to be replaced

regularly. (Any 5)

(5)

4.2 4.2.1 Direct current. (1) 4.2.2 • More compact.

• It is much lighter. • Use less current. • Uses lower ampere to weld. • More economical to use.

(5)

4.2.3 • Yes. • Can easily weld aluminium if you reverse the polarity of the

electrodes on the welding machine.

(2)



4.3 Make a neat, labelled sketch of the forehand welding technique when welding

with an oxy-acetylene welding apparatus. Marks will be allocated for: Labels 5 Sketch 2 Neatness 1

Neatness Correctness of the sketch

(8)

4.4 • When metal is heated, it expands • and when it cools down it shrinks. • The shrinking of welded metal, as well as weld runs, causes distortion of

sheets, when they cool down. • Shrinking takes place in all directions simultaneously • and therefore causes various types of distortion. (Any 4)

(4)

4.5 • It is the process where warn parts can be built up • by padding with a wear resistant metal.

(2)

[35]

Electrode

Welding Torch

Welding bead

Direction of travel

45°



QUESTION 5: TOOLS, IMPLEMENTS AND EQUIPMENT 5.1 5.1.1 Universal joint.

(1)

5.1.2 To manually grease the inner part of the universal joint, where lubrication is needed on a regular basis.

(1)

5.1.3 • Strong. • Not become loose. • Weight saving. • Must provide adequate/efficient protection. (Any 2)

(2)

5.2 • Release all chains. • Release all belts. • Clean and wash machine properly • Dry machine • Grease all moving parts • Paint where necessary • Cover whole machine (Any relevant answer) (Any 5)

(5)

5.3 5.3.1 • Sliding gearbox.

• Constant mesh gearbox. • Synchronised gearbox. • Automatic • Semi-automatic • Pre select • Tip tronic (Any 3)

(3)

5.3.2 Noisy/excessive wear.

(1)

5.4 5.4.1 Na x Da = Ng x Dg. Dg = Na x Da

Ng = 1 500 x 200 3 000 = 100 mm

(3)

5.4.2 • V-belts do not easily slip off pulleys. • V-belts draw tighter round pulleys when tension increases. • Lubrication is never necessary. • V-belts are relatively strong, and do not break easily under

normal circumstances. • Cold, moist conditions, age or use does not cause V-belts to

stretch or shrink. • V-belts last longer than flat belts.

(2)

5.4.3 To change the direction of rotation on the pump. (1)



5.5 5.5.1 • Driving power.

• Local availability of parts and service. • Rigidity of construction. • Simplicity of control mechanisms. • Driver comfort. • Versatility. • Proven reliability and durability. • Cost • Purpose • Who is the operator Skilled or unskilled (Any 5) (5)

5.5.2 • Type of use. (Pulling a trailer or heavy implement like a plough or ripper)

• Maximum drive requirements • Texture of the soil. (Clay or sand) • Type of tractor. (4x4 and 2x4) (4 wheels – 8 wheels)

(4)

5.6 5.6.1 • Welger system/Roller system

• Vermeer system/Belt or chain system

(2)

5.6.2 RECTANGULAR BALER ROUND BALER

a) Storage space optimally utilised.

a) One man operation.

b) Bales handled manually.

b) Low rope consumption.

c) Continuous baling process.

c) Simplistic working.

d) Bales stored easily.

d) Can bale until rain starts.

e) Transport space optimally utilised.

e) Roofed storage not necessary.

f) Bales easily handled f) Can be wrapped

(10)

(Any relevant answer) [40]



QUESTION 6: WATER MANAGEMENT 6.1 6.1.1 • Installation costs are very high.

• Blockages occur from time to time and are expensive to correct.

• The installation requires technical skills and knowledge.

(3)

6.1.2 • Trenches or ditches are dug to a depth of 0,5 m to 2 m. • The trench has a steady fall to enable it to carry away the

superfluous water which it collects from the surrounding soil. • At the bottom of the trench, bush, poles, stones or tiles (pipes)

are placed and then covered with earth. This helps with the movement of the water.

• The rocks or pipes are then covered with topsoil. • In this way the whole of the drained area may be used for the

cultivation of crops.

(5)

6.2 • Buried deep enough not be damage by implements. • Buried in sand. • Couplings must be water tight. • Lime layer 500 mm above pipe.

(3)

6.3 6.3.1 • Sewage is broken down by anaerobic bacteria in the first tank.

• Very little solids remain when the watery sewerage flows • to the second tank. • Only liquid sewerage remains and drains away through • the outlet pipe or stone trench.

(3)

6.3.2 • Do not build near boreholes/rivers or water sources. • It must be a suitable distance away from the house. • Not in the vicinity where people eat, wash or regularly work. • Drinking water installations.

(4)

6.3.3 • Sludge is not bio degradable • and therefore it will accumulate until the tank overflows • and therefore clog the drainage pipes and the soil into which

they drain.

(3)

6.3.4 • Use only toilet paper. • No plastics or non degradable materials. • No cigarette buds, rags etc. should get into the tank. • No disinfectants should be used. • No bleaches, oils. • Don’t over use

(5)


Copyright reserved

6.4 • To save water.

• To prevent over-irrigation. • To prevent under-irrigation.

(2)

6.5 • Between 3–5 metres • Dangerous, the sides may fall in.

(2)

[30]

TOTAL SECTION B:GRAND TOTAL:

160 200

Documents

GRAAD 12 NATIONAL SENIOR CERTIFICATE GRAD E 12 · Various options are provided as possible answ ers to the following questions. Choose the answer and make a cross (X) in the block